摘要:

Abstractα‐Hydro‐ω‐hydroxypoly(5‐chloro‐2‐hydroxy‐1,3‐phenylenemethylene)s (1a, b), the oligomeric condensation products from 4‐chloro‐2,6‐bis(hydroxymethyl)phenol and 4‐chlorophenol with hydrochloric acid in 1,4‐dioxane, could be completely dehalogenated at room temperature and atmospheric pressure with hydrogene/Raney‐Ni. The resulting oligomers2a, bwere esterified with acetic anhydride, and the esters3a, bwere subjected to a oligomer analogous Fries rearrangement to form the linear α‐hydro‐ω‐hydroxypoly(5‐acetyl‐2‐hydroxy‐1,3‐phenylenemethylene)s4aand4b. The characterization of the pr

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800801

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractNew photochromic polymers were prepared by deactivating living homo or block copolymers with various 2H‐chromene‐2‐spiro‐2′‐indolines (3a–3d). Classical anionic polymerization was used throughout this work. By varying the chemical nature of the blocks as well as that of the photochromic units, a series of novel materials was obtained and their structure and behaviour were

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800802

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractLithium amide catalyzed anionic polyaddition ofN,N′‐diethylethylenediamine (6) to 1,4‐divinylbenzene (9) was carried out to obtain a new type of polyamine possessing a polymerizable vinyl group at the chain end, a so‐called “macromer”. Analyses of the reaction and of the resulting polyamine by means of13C NMR and GPC revealed that this polyaddition reaction is a typical equilibrium reaction which is not accompanied with any side reactions, except with a possible cyclization reaction. The equilibrium constantsKand their temperature dependence were determined and compared with those of model reactions. The rate constantsk1of the first step reaction andk2of the second step were also determined in

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800803

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractN‐Trifluoroacetyl‐Nylon 66 (2) obtained by the reaction of Nylon 66 (1) with trifluoroacetic anhydride is very suitable as a polymeric reagent for the trifluoroacetylation of amines and alcohols. The advantages of2compared with low molecular trifluoroacetylating reagents are discussed. The selectivity against different substituted anilines and against structurally isomeric secondary amines was studied intensively by kinetic measureme

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800804

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe copolymerizations of aminoacetonitrile (AAN) with α‐aminopropionitrile (α‐APN), α‐aminoisovaleronitrile (α‐AVN), α‐aminoisocapronitrile (α‐ACN), andN‐methylaminoacetonitrile (MAAN) were carried out to obtain co‐oligoamidines by using basic catalysts such as bariumsec‐butoxide ((s‐BuO)2Ba) at 100°C in dioxane. The resulting co‐oligoamidines were converted into co‐oligopeptides by hydrolysis. The rate of the homopolymerization of aminonitriles decreased in the following order: AAN>α‐APN>MAAN>α‐AVN>α‐ACN. From the composition curves in the copolymerizations, the reactivity of AAN with respect to other aminonitriles was the following: AAN‐A

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800805

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe mechanism of radical formation from the radical initiator systemsN,N‐dimethylanilineN‐oxide (DMAO)/acid anhydride, was investigated by spin trapping technique. 2‐Methyl‐2‐nitrosopropane (BNO) was used as spin trapping reagent. In the DMAO/acetic anhydride system, both methyl andN‐methylanilinomethyl radicals were trapped by BNO as the corresponding amineN‐oxyl radicals. However, only ethyl and undecyl radicals were trapped from DMAO/propionic anhydride and from DMAO/lauric anhydride system, respectively. In the DMAO/benzoic anhydride system, the amineN‐oxyl radical derived fromN‐methylanilinomethyl radical and another amineN‐oxyl radical were observed. The latter one is likely to be derived from a radical formed by hydrogen abstraction from the methyl group of DMAO by a benzoyloxyl radical. When the concentrations of DMAO and benzoic anhydride were lowered, phenyl radical was also trapped. From these findings, the initiation mechanism of vinyl polymerization with the DMAO/acid anhydride systems was pro

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800806

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe heat of solution and the osmotic pressure of bovin hemoglobin in aqueous solution have been measured at 298 K using a twin microcalorimeter and an osmometer. The heat of association, ΔH, from calorimetric measurement and the association equilibrium constant,K, from osmometric measurement have been estimated, respectively. Also the thermodynamic quantities of the hemoglobin molecule which associates from 2αβ to the original α2β2form are calculated. In all systems of the hemoglobin solutions, the value of dissociation equilibrium constant,K', calculated as the reciprocal ofK, and that of ΔHseem to be of comparable order to those determined by the other investig

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800807

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractAtactic polypropylene was irradiated in vacuo, in O2, and in Cl2with60Co γ‐rays, and changes in polymer structure were investigated by means of IR and ESR measurements of the irradiated polymer and by mass spectrometry of gaseous products. The irradiation in vacuo mainly produced H2with small amounts of lower hydrocarbons (C1– C3). As a radical product, only an alkyl radical was observed. The increase in IR absorption at 886 cm−1indicated the formation of vinylidene unsaturation. The irradiation in O2produced oxygenated products such as CO, CO2, and H2O with a reduced amount of H2. In the irradiation in Cl2, HCI was a main gaseous product. The existence of CCl bonds and a small amount of polyenyl groups in the irradiated polymer indicated that the radiation‐induced chlorination of APP was partly followed by elimination of HCl through a zip

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800808

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractThe counterions appearing in the mechanism of the cationic polymerization are able to decay according toand so give rise to termination reactions. For the model systems (C6H5)3C⊕MtX⊖n+1(Mt = B, Al, Sn, P, As, Sb, In, Ti, Fe; X = F, Cl, Br) the decay has been investigated by spectroscopic and conductometric methods. The overall decay rate constantkzis hardly influenced by traces of water (cH2O<10−3mol.l−1) and by structure variations of the cation. On the other hand,kzincreases by decreasing the concentration of the salt. When the structure is variedkzincreases with decreasing donor strength of the ligands X; the sensitivity of the anion to changes in the ligand sphere increases corresponding to the ionization potential of the central atom Mt. Addition of tetracyanoethylene raises the stability of the anions.The results can be explained by the HSAB principle and fit well in a scheme of stabilization of anions by ac

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800809

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractIonic polymer‐polymer interaction was studied in aqueous solution for poly(L‐lysine) (PLL) and sulfated poly(vinyl alcohol) (PVS) as functions of pH, the degree of sulfation, the functional unit mole ratio of the two polymers and temperature by means of circular dichroism and viscosity measurements. In all the cases studied, strong inter‐polymer complexes were formed at the functional unit mole ratio (VS)/(LL) higher than 1. Although PLL itself is well known to take the α‐helical conformation at such a high pH as 11, the PLL conformation in the PLL/PVS complexes did not depend on pH but on the degree of sulfation: at room temperature, PLL took random coil conformation in PLL/PVS‐25 (25: degree of sulfation in mole‐%) and PLL/PVS‐30, and the α‐helical conformation (helicity of 70%) in PLL/PVS‐46 and PLL/PVS‐95. Models for the complex structures are postulated. Methanesulfonic acid did not influence the conformational transition of PLL, supporting that a polymer effect took place in the complex formation between PLL and PVS. Thermal effect on the PLL conformation in the comp

ISSN:0025-116X    

DOI:10.1002/macp.1979.021800810

出版商:Hüthig&Wepf Verlag    

年代:1979

数据来源: WILEY